Step |
Hyp |
Ref |
Expression |
1 |
|
idn1 |
|
2 |
|
simp1 |
|
3 |
1 2
|
e1a |
|
4 |
|
simp2 |
|
5 |
1 4
|
e1a |
|
6 |
|
pm4.39 |
|
7 |
6
|
ex |
|
8 |
3 5 7
|
e11 |
|
9 |
|
simp3 |
|
10 |
1 9
|
e1a |
|
11 |
|
pm4.39 |
|
12 |
11
|
ex |
|
13 |
8 10 12
|
e11 |
|
14 |
|
df-3or |
|
15 |
14
|
bicomi |
|
16 |
|
bitr3 |
|
17 |
16
|
com12 |
|
18 |
13 15 17
|
e10 |
|
19 |
|
df-3or |
|
20 |
19
|
bicomi |
|
21 |
|
bitr |
|
22 |
21
|
ex |
|
23 |
18 20 22
|
e10 |
|
24 |
23
|
in1 |
|